Ejectable underwater sound source recovery assembly

ABSTRACT

For ejectable mounting on a mobile device (e.g., a rocket) intended to travel over water to facilitate location and recovery of the device when submerged, an underwater sound source is mounted in a mounting bracket which is attachable to the device so as to detach or eject upon impact, destruction, or automatically at a prescribed time or under prescribed conditions. Preferred attachment means for some uses comprise bolts which are adapted to fracture upon impact with the water. A length of flexible line is coiled within a line housing coupled to the mounting bracket such that the line will freely feed out from the housing when pulled by one free end thereof, which free end is adapted for coupling with the device, the other end being coupled with the sound source and its bracket. This allows ejection of the bracket with the sound source, while maintaining a flexible connection between the mobile device and the sound source. An aerodynamic fairing which provides a clean aerodynamic surface during flight is adapted to separate from the bracket upon ejection from the mobile device. During recovery, the sound source is located by a diver, and the line leads to the device, which may be a rocket buried in mud on the ocean floor.

United States Patent [1 1 Irick I EJECTABLE UNDERWATER SOUND SOURCERECOVERY ASSEMBLY [75] Inventor: Stephen C. Irick, Hampton, Va. [73]Assignee: The United States of America as I represented by theAdministrator of the National Aeronautics and Space Administration,Washington, DC.

[22] Filed: July 19, 1972 [21] Appl. No.: 273,240

[52] US. Cl. 3,40/5 R, 340/8' R, 340/l2 R {51] Int. Cl. H04b 11/00 [58]Field of Search.;... 340/2, 3 A, 4 R, 340/5R,6R,8R,10,12R,9

[56] References Cited I UNITED STATES PATENTS 3,005,l87 lO/l96l- Mayes340/6 R 3,249,913 5/l966 Smyth et al 340/10 Primary EQraminer-Richard A.Farley Attorney-Howard .l. Osborn et al.

[s71 ABSTRACT For ejectable mountingon a mobile device (e.g., a

Jan. 1, 1974 rocket) intended to travel over water to facilitatelocation and recovery of the device when submerged, an underwater soundsource is mounted in a mounting bracket which is attachable to thedevice so as to detach or eject upon impact, destruction, orautomatically at a prescribed time or under prescribed conditions.Preferred attachment means for some uses comprise bolts which areadapted to fracture upon impact with the water. A length of flexibleline is coiled within a line housing coupled to the mounting bracketsuch aerodynamic fairing which provides a clean aerodynamic surfaceduring flight is adapted to separate from the bracket uponejection fromthe mobile device. During recovery, the sound source is located by a Idiver, and the line leads to the device, which may be a rocket buried inmud on the ocean floor.

11 Claims, 3 Drawing Figures 1 EJECTABLE UNDERWATERSOUND SOURCE RECOVERYASSEMBLY ORIGINOF INVENTION The invention described herein was made byan employee of the United States Government and may be manufactured andused by or for the Governmentfor governmental purposeswithout thepayment of any royalties thereon or therefor.

FIELD OF THE INVENTION This invention relates to ejectableunderwatersound source recovery assemblies, that is, underwater sound sourceassemblies that are ejectably mounted on rockets, aircraft, watercraft,precious cargo, or any mobile device that may travel over water, tofacilitate location and recovery of the device when submerged. In itspreferred embodimentand use, the invention is particularly useful in therecovery of spent rocket motors that bury in the ocean floor uponimpact.

BACKGROUND AND SUMMARY Location and recovery of objects and devices fromthe floor of a body of water, such as the ocean floor, is oftenextremely difficult because of the conditions involved. For instance,such objects may bury themselves in mud on the ocean floor. Even if notburied, they may be in a muddy or murky area where a divers visibilityis extremely limited, either because of the natural murkiness or becauseof the mud and murkiness stirred up by the diver moving around in thearea. Location and recovery of such objects can be facilitated somewhatif they include an underwater sound source which can be detected by adiver. I-lowever, difficulties are encountered even when such soundsources are used. For instance, if the object to be recovered wasoriginally airborne, the sound source may be damaged or destroyed when.the object initially impacts with the water surface. If the object vwasoriginally airborne or surface borne, the sound source may be crushedduring the impact of the object with the ocean floor. Even if the soundsource is not damaged or crushed, its effectiveness will besubstantially reduced if the object and the sound source bury deeply inthe ocean floor. Finally, even if the object andthe sound source settleon the ocean floor with the sound source undamaged, there still remainsa problem in the final pinpointing and locating of the object by thediver, because of the fact that the divers ability to detect thedirection of the sound source diminishes as the diver approaches thesound source. Thus, the diver may home in on the sound source so as toplace himself in thegeneral area of the object to be recovered, butsince his ability to sense the direction of the sound source is nowsubstantially diminished, theremay be substantial further delays inactually locatingthe object, and the diver may compound the delaysbystirring up the floor in the area of the object and contributing tothe murkiness in the area so as to limit his visibility. In fact, in theend the diver may be forced tolocate the object simply by feel.

With the foregoing in-mind, it is an object of this invention to providean underwater sound source assembly that may be ejectably mounted onrockets, aircraft, watercraft, precious cargo, or other such devices, tofatcilitate location and recovery of the device when submerged. It is amore particular object of this invention to provide such an assemblywhich is attachable to the object or device so as to detach or ejectupon impact, destruction or automatically at a prescribed time or underprescribed conditions. It is still a further object of this invention toprovide such an assembly which will not be damaged upon impact orcrushed upon settling on the ocean floor, which will be located awayfrom the object to be recovered but will be connected thereto by aflexible line, and which will facilitate locating the object after thediver reaches the general area even though his visibility may besubstantially limited.

In general, my invention utilizes a conventional underwater soundsource, modified with an attachment point for receiving one end of aflexible line. The sound source is mounted in a mounting bracket whichis attachable to the device so as to detach or eject upon impact,destruction, or automatically at a prescribed time or under prescribedconditions. Preferred attachment means for some uses comprise boltswhich are adapted to fracture upon impact with the water, but otherattachment means may be used. For instance, automatically detonatedexplosive bolts could be used. The sound source may also be attached tothe fin of a rocket motor which is known to shear from the rocket uponimpact with the water, or it may be placed internally on a part such asthe rocket nozzle which is also known to separate from the rest ofthe'rocket upon impact with the water. Thus, the sound source may belocated on various parts and in different places as long as separationfrom the main mobile device takes place before, on, or after submerging.

A length of flexible line is coiled within a line housing coupled to themounting bracketsuch that the line will freely feed out from the housingwhen pulled by one free end thereof, which free end isadapted forcoupling with the device, the other end being coupled with the soundsource and its bracket. This allows ejection of the bracket with thesound source, while maintaining a flexible connection between the mobiledevice and the sound source. Where the device or object is airborne,such as a rocket or missile, an aerodynamic fairing for the bracket isadapted to separate from the bracket, exposing the blunt surfaces of thebracket such that there will be a substantial drag on the sound sourceassembly to insure that it separates substantially from the object ordevice after impact with the water. During recovery, the sound sourcewill lead a diver to the general area, where he will locate the soundsource and be led to the device by the flexible line. If visibilityconditions are such that difficulty is encountered in pinpointing thesound source, the diver may maneuver in a set pattern over the areauntil he encounters the line connecting the sound source and the objectto be recovered. Thus, even though visibility conditions may beextremely poor, precluding a direct sighting of any object, the extendedline enhances the recovery capability through dragging methods.

Other and further objects, advantages and features of my invention willbecome apparent to those skilled in the art from the ensuing descriptionof a preferred embodiment for use in connection with the location andrecovery of spent rocket motors, which usually bury in the ocean floorupon impact, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat diagramaticelevation view of a rocket motor with a preferred embodiment of myinvention mounted on the aft launch shoe.

FIG. 2 is a bottom plan view of the assembly of FIG. 1 showing moredetails of the ejectable underwater sound source assembly itself and itsmanner of connection to the aft launch shoe.

FIG. 3 is a fragmentary illustration showing the manner in which theline housing, the line, the mounting bracket. and the sound source areassembled.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings,reference character 1 designates a conventional rocket motor, forinstance, an Honest John rocket motor of a well-known type, providedwith an aft launch shoe 2. An ejectable underwater sound source recoveryassembly in accordance with a preferred embodiment of my invention isdesignated generally by reference character 3. Assembly 3 includes anunderwater sound source 4, which may be considered as a conventionalsound source modified by the addition of an attachment point 5. Anexemplary sound source is model N15A2IO, manufactured by DukaneCorporation, St. Charles, Illinois. The body of sound source 4 isgenerally cylindrical, and attachment point 5 may form part of the casecover at the battery end. The general type of sound source is oftenreferred to as a pinger.

The mount or bracket for the pinger or sound source is shown generallyat 6, and comprises an elongate body member 7 formed with two brackets 8and 9 standing proud from body member 7. A blind ended bore 10in bracket8 receives one end of pinger 4. Elongate body member 7 is formed withbolt holes 11 to receive mounting bolts 12 for connecting the assemblyto the launch shoe 2. In this embodiment, mounting bolts 12 are designedto fracture upon impact with the water, and thus are formed withnecked-down sections 13 which will rupture under a predetermined force.A pinger or source retainer 14 comprises a thin metal bulkhead throughwhich attachment point 5 passes, this retainer 14 being located betweenthe faces of bracket 9 and mounting flange 15 of line housing 16. Thebulkhead serves as a retainer to hold the line 22 in the housing 16before final assembly, and prevents the line from interfering with themating surfaces during assembly. Mounting bolts I7 connect mountingflange 15 and line housing 16 to bracket 9 of pinger mount 6. Coiledwithin line housing 16 is a length of line 18, which may comprise to 30feet of 550 pound test parachute riser line. Line 18 has an outer loopedend 19 which extends through a pull-out disc 20, loop 19 preferablybeing made by forming a loop around a conventional thimble. Pullout disc20 is designed so as to maintain the line 18 and loop 19 in place undernormal conditions, but to release the loop and line under apredetermined force so as to permit the line to play out freely from theline housing.

A wire rope 21, which may be approximately three feet long, connectsinner loop end 22 of line 18 with attachment point 5 of pinger 4. Aconnecting cable 23 connects loop 19 of line 18 with self-locking screws24 on launch shoe 2 to complete the flexible connection betweenattachment point 5 and launch shoe 2.

An aerodynamic fairing 25 is located at the forward end of pinger mount6 adjacent the forward face of bracket 8, and includes a flat member 26extending under mount 6. Screws 12, passing through member 26,constitute the only connection holding fairing 25 and pinger mount 6 onthe launch shoe, and thus it will be readily apparent that fairing 25will separate from the assembly 3 when assembly 3 separates from launchshoe 2 upon rupture of mounting screws 12.

When assembled, pinger 4 is firmly suspended over elongate body member 7by the blind ended bore 10 at one end and a correspondingthrough-opening in bracket member 9 at the other end. When mounting theassembly there should be minimum slack in connecting cable 23 so as toavoid any possibility of snagging on projections.

Although mounting bolts adapted to rupture upon impact have been used inthe illustrated preferred embodiment, it will be understood thatexplosive bolts could be used, adapted to detonate at a predeterminedtime, or at a predetermined altitude, or upon termination of rocketmotor thrust.

In use of the preferred embodiment, when the rocket motor impacts thewater the bracket separates from the motor because of the rupture of themounting bolts. The nylon cord remains attached to the motor, and is fedout of the line housing as the motor and bracket separate. Theaerodynamic fairing separates from the bracket when the bracketseparates from the motor, thus producing a drag configuration thatprevents the assembly from burying beneath the ocean floor.

The underwater sound source or attached cord is located by the diver aspreviously described, and the attached cord leads to the buried motor.

It is to be understood that the foregoing illustrated and describedembodiment is exemplary of my invention, and is not limiting of it. Thescope of the invention is as defined in the subjoined claims, taken inconjunction with the previous description and illustrations.

I claim:

1. For ejectable mounting in or on a mobile device intended to travelover water to facilitate location and recovery of at least a portion ofthe device when submerged, an underwater sound source assemblycomprising an underwater 'sound source, a mounting bracket firmlycontaining said sound source, a line housing coupled to said mountingbracket, a length of flexible line coiled within said line housing suchthat the line will freely play out from the line housing when pulled byone free end thereof, said line having one fixed end coupled with saidassembly and one free end terminating in a connector accessible fromoutside said line housing to permit ready connection of said free endwith a mobile device in or on which the assembly is to be mounted, meansfor normally retaining said line in said line housing and releasing saidline only in response to a predetermined pulling force on said free end,and coupling means adapted to firmly couple said assembly to a mobiledevice such that said assembly will release therefrom in response to apredetermined condition, leaving the assembly connected to the deviceonly by said line.

2. An assembly as claimed in claim 1 wherein said coupling meanscomprise bolt means for rupturing under a predetermined force.

3. An assembly as claimed in claim 1 further comprising an aerodynamicfairing at one end of said assembly and coupled thereto to releasetherefrom when said assembly releases from a mobile device in or onwhich it is ejectably mounted.

4. An assembly as claimed in claim 3 wherein said aerodynamic fairing iscoupled to said assembly by said coupling means. i

5. An assembly as claimed in claim 4 wherein said one end of saidassembly is relatively blunt, wherein said assembly has a mounting faceto lie against a surface of the device in or on which it is mounted, andwherein said aerodynamic fairing includes a portion adapted to extendalong said mounting face to be embraced firmly between said mountingface and said surface.

6. An assembly as claimed in claim 1 wherein said mounting bracketincludes an elongate body member with two bracket members standing proudtherefrom at opposite ends thereof, means on the inner face of one ofsaid bracket members for insertably receiving and supporting one end ofsaid sound source, a throughopening in the other of said bracket membersthrough which said sound source can be longitudinally inserted andremoved, said through-opening supporting the other end of said soundsource, and wherein said line housing is removably connected to theouter face of said other bracket member to cover said through-bore.

7. An assembly as claimed in claim 6 wherein said sound source has aline attachment face at its said other end projecting from saidthrough-bore into said line housing and wherein said fixed end of saidline is coupled to said attachment point.

8. An assembly as claimed in claim 6 wherein said sound source issuspended clear of said elongate body member between said two bracketmembers.

9. An assembly as claimed in claim 8 in combination with an aeronauticaldevice and coupled thereto by said coupling means and said free endconnector of said line, said coupling means comprising connectors forautomatically releasing upon impact of the aeronautical device with abody of water over which the device has flown.

10. An assembly as claimed in claim 1 in combination with anover-water-travelling device and coupled thereto by said coupling meansand said free end connector, said coupling means comprising connectorsreleasable automatically upon occurrence of a predetermined condition.

1 1. An assembly as claimed in claim 1 in combination with anaeronautical device and coupled by said coupling means to a part thereofwhich will separate from the device upon occurrence of a predeterminedcondition, said free end connector of said line being connected toanother part of said device.

1. For ejectable mounting in or on a mobile device intended to travelover water to facilitate location and recovery of at least a portion ofthe device when submerged, an underwater sound source assemblycomprising an underwater sound source, a mounting bracket firmlycontaining said sound source, a line housing coupled to said mountingbracket, a length of flexible line coiled within said line housing suchthat the line will freely play out from the line housing when pulled byone free end thereof, said line having one fixed end coupled with saidassembly and one free end terminating in a connector accessible fromoutside said line housing to permit ready connection of said free endwith a mobile device in or on which the assembly is to be mounted, meansfor normally retaining said line in said line housing and releasing saidline only in response to a predetermined pulling force on said free end,and coupling means adapted to firmly couple said assembly to a mobiledevice such that said assembly will release therefrom in response to apredetermined condition, leaving the assembly connected to the deviceonly by said line.
 2. An assembly as claimed in claim 1 wherein saidcoupling means comprise bolt means for rupturing under a predeterminedforce.
 3. An assembly as claimed in claim 1 further comprising anaerodynamic fairing at one end of said assembly and coupled thereto torelease therefrom when said assembly releases from a mobile device in oron which it is ejectably mounted.
 4. An assembly as claimed in claim 3wherein said aerodynamic fairing is coupled to said assembly by saidcoupling means.
 5. An assembly as claimed in claim 4 wherein said oneend of said assembly is relatively blunt, wherein said assembly has amounting face to lie against a surface of the device in or on which itis mounted, and wherein said aerodynamic fairing includes a portionadapted to extend along said mounting face to be embraced firmly betweensaid mounting face and said surface.
 6. An assembly as claimed in claim1 wherein said mounting bracket includes an elongate body member withtwo bracket members standing proud therefrom at opposite ends thereof,means on the inner face of one of said bracket members for insertablyreceiving and supporting one end of said sound source, a through-openingin the other of said bracket members through which said sound source canbe longitudinally inserted and removed, said through-opening supportingthe other end of said sound source, and wherein said line housing isremovably connected to the outer face of said other bracket member tocover said through-bore.
 7. An assembly as claimed in claim 6 whereinsaid sound source has a line attachment face at its said other endprojecting from said through-bore into said line housing and whereinsaid fixed end of said line is coupled to said attachment point.
 8. Anassembly as claimed in claim 6 wherein said sound source is suspendedclear of said elongate body member between said two bracket members. 9.An assembly as claimed in claim 8 in combination with an aeronauticaldevice and coupled thereto by said coupling means and said free endconnector of said line, said coupling means comprising connectors forautomatically releasing upon impact of the aeronautical device with abody of water over which the device has flown.
 10. An assembly asclaimed in claim 1 in combination with an over-water-travelling deviceand coupled thereto by said coupling means and said free end connector,said coupling means comprising connectors releasable automatically uponoccurrence of a predetermined condition.
 11. An assembly as claimed inclaim 1 in combination with an aeronautical device and coupled by saidcoupling means to a part thereof which will separate from the deviceupon occurrence of a predetermined condition, said free end connector ofsaid line being connected to another part of said device.